Contents
2001
Volume: 21 Issue 6
30 Article(s)
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Atmospheric Optics and Oceanic Optics
Numerical Simulation of an Adaptive Optics System: Dynamic ControlProcess and
[in Chinese], [in Chinese], and [in Chinese]
A numerical simulation of the dynamic control process in an AO system is carried out to complete a comprehensive numerical simulation of an AO system. In comparison to the theoretical analyses of automatic control, the numerical simulation of dynamic control process in an AO system is advantageous. The frequency responA numerical simulation of the dynamic control process in an AO system is carried out to complete a comprehensive numerical simulation of an AO system. In comparison to the theoretical analyses of automatic control, the numerical simulation of dynamic control process in an AO system is advantageous. The frequency response characteristics are closely related to the dynamic control performance of an AO system. A numerical simulation of the frequency response characteristics in an AO system is presented as well. The numerical simulation results agree with the experimental data excellently. The simulation calculation results of frequency response by using composite input of multiple frequencies are comparable to the single-frequency simulation results quite well and usable to determine the practical parameters of bandwidth and margins. The computing time of multi-frequency simulation calculation is much shorter than that of the single-frequency simulation calculation. The performances of an AO system can be effectively investigated by means of a combination of the numerical simulation of frequency response characteristics with that of long-exposure Strehl ratio..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 667 (2001)
Fiber Optics and Optical Communications
Third-Order Dispersion Compensation in Picosecond Pulse Transmission System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In a second order dispersion and third order dispersion compensation optical fiber links system, 1 ps Gaussian pulse′s transmission is simulated. It is concluded that as second order dispersion compensation can avoid pulse broadening, third order dispersion compensation not only can avoid pulse broadening, but also eliIn a second order dispersion and third order dispersion compensation optical fiber links system, 1 ps Gaussian pulse′s transmission is simulated. It is concluded that as second order dispersion compensation can avoid pulse broadening, third order dispersion compensation not only can avoid pulse broadening, but also eliminate pulse edge′s oscillating and temporal shift of pulse peak. The eye diagrams of 64 bit random data pattern of 100 Gb/s Gaussian pulse series after transmissing 2000 km are obtained. It is shown through the clear eye diagram that third dispersion compensation system can efficiently improve the transmission performance of short pulse..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 652 (2001)
Modulation Instability of Femtosecond Optical Pulses in Decreasing Dispersion Fibers
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Modulation instability of femtosecond optical pulses in decreasing dispersion fibers is investigated. The expression of gain spectrum is obtained. It is found that the broadest spectral width of the gain spectrum can be obtained when the dispersion parameter of the decreasing dispersion fibers fits to a certain equatioModulation instability of femtosecond optical pulses in decreasing dispersion fibers is investigated. The expression of gain spectrum is obtained. It is found that the broadest spectral width of the gain spectrum can be obtained when the dispersion parameter of the decreasing dispersion fibers fits to a certain equation, and the third order dispersion does not contribute to modulation instability, the range of gain spectrum is narrowed and the growth rate of amplitude is slowed down by self-steepening, and the Raman effect alters the range of modulation instability..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 656 (2001)
Stimulated Raman Scattering in Raman Gain Separated Fiber
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The Raman gain separated fiber is designated. The analytic solutions of N-channels stimulated Raman scattering (SRS) steady-state coupling wave equation in the fibers is given. As considering the SRS cross coupling among the N-channels, the analytic solutions are applicable to arbitrary channel separation and input phoThe Raman gain separated fiber is designated. The analytic solutions of N-channels stimulated Raman scattering (SRS) steady-state coupling wave equation in the fibers is given. As considering the SRS cross coupling among the N-channels, the analytic solutions are applicable to arbitrary channel separation and input photon fluxes. These results can be used to analyze and design the optical fiber communication systems, Raman fiber amplifier and lasers. Finally, the analytic solution is compared with numerical one, both are in very good agreement..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 660 (2001)
Effect of Longitudinal Zero-Dispersion Wavelength Variation along Dispersion-Shifted Fiber on the Four-Wave Mixing Conversion Efficiency
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The four-wave mixing behavior near the zero-dispersion region of the dispersion-shifted fiber is theoretically studied and the case in which several dispersion-shifted fibers with different zero-dispersion wavelengths are combined together for four-wave mixing is considered. The results show that the four-wave mixing iThe four-wave mixing behavior near the zero-dispersion region of the dispersion-shifted fiber is theoretically studied and the case in which several dispersion-shifted fibers with different zero-dispersion wavelengths are combined together for four-wave mixing is considered. The results show that the four-wave mixing in all the dispersion-shifted fibers contributes to the total conversion efficiency, the parametric gain is apparent and the three-dimension efficiency line is very complicated when the signal-pump wavelength separation is small enough..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 664 (2001)
Fourier Optics and Signal Processing
Three-Dimensional Surface Profilometry Using Color-Coded Projection Grating
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A method of digital coding of grating by using color strips is presented. White, red, green, blue and their complementary colors, black, cyan, magneta and yellow are used to code the grating based on the binary system. The white and the black stripes are used to represent 1 and 0 on the fourth bit, red and cyan to reprA method of digital coding of grating by using color strips is presented. White, red, green, blue and their complementary colors, black, cyan, magneta and yellow are used to code the grating based on the binary system. The white and the black stripes are used to represent 1 and 0 on the fourth bit, red and cyan to represent 1 and 0 on the third bit, the green and magenta to represent 1 and 0 on the second bit and the blue and yellow to represent 1 and 0 on the first bit of the binary system, respectively. There are 64 stripes in one period. The space period of the projection grating is large enough for measuring the surface profiles of normal objects. Since each strip has only one logical state, the system possesses good disturbance-resistance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 687 (2001)
Spectral Satellite Image Compression Based on Wavelet Transform
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The characters of spectral satellite images are analyzed and a new spectral satellite image compression method based on region-enhanced wavelet transform and set partitioning in hierarchical tree (SPIHT) coding is presented which offered a satisfied compressing result by enhancing the wavelet coefficients of the seriouThe characters of spectral satellite images are analyzed and a new spectral satellite image compression method based on region-enhanced wavelet transform and set partitioning in hierarchical tree (SPIHT) coding is presented which offered a satisfied compressing result by enhancing the wavelet coefficients of the serious image data area. A few spectral satellite images are tested and the experimental results show that this method has more advantages over other methods reported so far for spectral satellite image compression..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 691 (2001)
Experimental Study on the Properties of Autocorrelation Function of Image Speckles Produced by Weak Random Screens
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By measuring the parameters of weak random screens with AFM and constructing a specially designed setup with gated integrator, the properties of autocorrelation functions of speckle fields produced by weak random screens on the focused and defocused image planes are studied experimentally. It is found that: 1) as the sBy measuring the parameters of weak random screens with AFM and constructing a specially designed setup with gated integrator, the properties of autocorrelation functions of speckle fields produced by weak random screens on the focused and defocused image planes are studied experimentally. It is found that: 1) as the surface roughness increases, the average size of the speckle grains on the focused image plane decreases, and the spatial separation range of the secondary maximum of the autocorrelation functions is reduced while its fluctuation is increased; 2) as the defocus increases, the autocorrelation function of the speckle intensity on the defocused image plane decreases more smoothly and the first order minimum and the secondary maximum become indistinct or even disappear..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 696 (2001)
Instrumentation, Measurement and Metrology
Beam Scanning and Inversion Method for Lidar Detecting Wind
[in Chinese], and [in Chinese]
Utilizing lidar to obtain the wind velocity along the line of sight by Doppler shift and then inverting these velocity vectors to real atmosphere wind group speed is a very important purpose of laser lidar. The technique of using a conical scanning manner known as velocity azimuth display based on single laser Doppler Utilizing lidar to obtain the wind velocity along the line of sight by Doppler shift and then inverting these velocity vectors to real atmosphere wind group speed is a very important purpose of laser lidar. The technique of using a conical scanning manner known as velocity azimuth display based on single laser Doppler velocimetry (LDV) system is described. The horizontal and vertical wind sections of the observed field can be obtained by spatial analytic geometry operation and analysis based on the four orthogonal points vector which located on the scanning cone′s vertical section. Then inverting these vectors to the observed wind field..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 720 (2001)
Development of Lidar and Experimental Research for Measuring Atmospheric Aerosol
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new technique for measuring atmospheric aerosol characteristics using YAG lidar with iodine cell filter has been developed in the world. The theoretical analysis of the YAG lidar system was given and experimental YAG lidar system was built with 300 mm aperture receiving telescope and 150 mJ YAG laser pulse energy, asA new technique for measuring atmospheric aerosol characteristics using YAG lidar with iodine cell filter has been developed in the world. The theoretical analysis of the YAG lidar system was given and experimental YAG lidar system was built with 300 mm aperture receiving telescope and 150 mJ YAG laser pulse energy, assessment of the lidar system performance was given through numerical simulations and primary experiments. Backscattering signals from atmosphere were measured. The data measured show that theoretical analysis and experiment results are coincident..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 724 (2001)
Design of an Infrared Spectroscopic Ellipsometer Using Double-Fourier-Transform
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new type of infrared spectroscopic ellipsometer has been designed and constructed. A double-Fourier-transform method, i.e. Fourier transforms carried out as both functions of the photon energy and azimuthal angle, is used. Using the configuration of synchronous rotation of the polarizer and analyzer (RAP), and accordA new type of infrared spectroscopic ellipsometer has been designed and constructed. A double-Fourier-transform method, i.e. Fourier transforms carried out as both functions of the photon energy and azimuthal angle, is used. Using the configuration of synchronous rotation of the polarizer and analyzer (RAP), and according to four cosine frequencies of Fourier transform, the optical constants can be obtained with any one of two sets of ac signal calculations. After a revised model being used to correct the data error arising from the slight anisotropy of analyzer the data self-consistency is improved to be better than 1% by comparing two sets of data. The spectra of the dielectric function for a Au film sample were measured and fitted with the Drude model. The result shows a very good agreement between experiment and theory..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 729 (2001)
Analysis of Measuring Condition for Principle Angle in Spectroscopic Ellipsometry
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The measuring condition for principle angle in spectroscopic ellipsometry is analyzed. As the incident angle is equal to principle angle θ p, the phase angle of ellipsometry parameters is 90°. It gives a way to obtain θ p from numerical calculation and analytic equation as the dielectric function of the material iThe measuring condition for principle angle in spectroscopic ellipsometry is analyzed. As the incident angle is equal to principle angle θ p, the phase angle of ellipsometry parameters is 90°. It gives a way to obtain θ p from numerical calculation and analytic equation as the dielectric function of the material is known, and the amplitude ρ p0 of ellipsometry parameters can be calculated accordingly. Higher precision of data can be acquired as measuring at incident angle of θ p. The experimental results of Δ p and ρ p0 correspond very well with the calculated ones. The calculation formulas and methods given in this work can be applied to other spectroscopic experiments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 734 (2001)
Study of Multi-Stage Optical Detection with Optically Erased Two-Beam Coupling
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The method of multi-stage optical detection is presented based on the principle of optically erasing and two-beam coupling. The theoretical formula about the device is built by using the coupling wave equation and band-transport model. An experimental demonstration is done by using Ce∶KNSBN crystals and He-Ne laser. ThThe method of multi-stage optical detection is presented based on the principle of optically erasing and two-beam coupling. The theoretical formula about the device is built by using the coupling wave equation and band-transport model. An experimental demonstration is done by using Ce∶KNSBN crystals and He-Ne laser. The feasibility of the method is proved by theoretical analysis and experimental demonstration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 737 (2001)
Lasers and Laser Optics
Computation of Peak Gain Efficiency of Ni-Like Kr Based on OFI
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
By use of some atom parameters in optical-field-ionized (OFI) plasmas obtained from the extended Cowan program based on Maxwell to suit any electron distribution with the help of additional program, the peak gain coefficient of Ni-like Kr system is calculated for the ion densities of 1×10 17 cm -3 and 3.2×10 By use of some atom parameters in optical-field-ionized (OFI) plasmas obtained from the extended Cowan program based on Maxwell to suit any electron distribution with the help of additional program, the peak gain coefficient of Ni-like Kr system is calculated for the ion densities of 1×10 17 cm -3 and 3.2×10 17 cm -3 respectively after considering Doppler broadening and natural broadening. The theoretic peak gain coefficients of 14 cm -1 and 141 cm -1 are obtained respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 702 (2001)
Theoretical Investigation of ISPI X-Ray Lasers in C and N
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A model employing five energy levels and a fit time-varying linear increase of photon pumping rate of X-ray source is proposed to analyze the gain of inner-shell photoionization (ISPI) X-ray laser in C. The deduced analytical expressions for the time of the onset of the peak gain and its peak value reveal the effects oA model employing five energy levels and a fit time-varying linear increase of photon pumping rate of X-ray source is proposed to analyze the gain of inner-shell photoionization (ISPI) X-ray laser in C. The deduced analytical expressions for the time of the onset of the peak gain and its peak value reveal the effects of Auger decay, electron impact ionization, the density of lasing medium and the increase rate of pumping rate on the duration and peak value of the laser gain. The requirement on the intensity of the driving ultra short pulse (USP) laser is estimated and the effect of changing the USP laser pulse duration on the peak gain is also given in this paper. Moreover, the model is used to estimate the requirements on the driving USP laser for ISPI X-ray laser in N..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 706 (2001)
Realization of Wide Band Tunable Solid-State Dye Optical Amplification
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Amplified spontaneous emission (ASE) in organic dye DCM doped PMMA and DCM doped PMMA/silica gel hybrid material planar waveguide are investigated. By controlling of the refractive index and the thickness of the waveguide, the ASE wavelength can be seleted in a wide range and wavelength tuning is realized. The tuning rAmplified spontaneous emission (ASE) in organic dye DCM doped PMMA and DCM doped PMMA/silica gel hybrid material planar waveguide are investigated. By controlling of the refractive index and the thickness of the waveguide, the ASE wavelength can be seleted in a wide range and wavelength tuning is realized. The tuning range can reach 30 nm. The method can be applied to the wide band tuning of solid-state tunable lasers and optical amplifiers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 712 (2001)
Effect of Synchronization Trigger on Output Characteristic of Multiple-Electrode-Pair Laser
[in Chinese], [in Chinese], and [in Chinese]
In the experiments of the output characteristic from a multiple-electrode-pair laser, keeping the discharge parameters (such as pressure, voltage, discharge volume and so on) changeless, when several electrode-pairs are triggered in the same time, the laser pulse energy enhances nonlinearly. The experimental rules are In the experiments of the output characteristic from a multiple-electrode-pair laser, keeping the discharge parameters (such as pressure, voltage, discharge volume and so on) changeless, when several electrode-pairs are triggered in the same time, the laser pulse energy enhances nonlinearly. The experimental rules are summed up and the effects of the interaction of several discharge sections on the intracavity photon density and cavity efficiency are considereds and the reasons of nonlinear energy enhancement are analyzed, and a theoretical model is set up. The theoretical analysis agrees with the experiments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 716 (2001)
Materials
Characterization of CVD Diamond Film/Porous Silicon Composite
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A novel passivation technology of porous silicon (PS) surface, i.e., depositing diamond film on the PS surface by microwave plasma assisted chemical vapor deposition (MPCVD) method, was developed. The morphologies, structure and photoluminescence (PL) of porous silicon and diamond film were characterized using atomic fA novel passivation technology of porous silicon (PS) surface, i.e., depositing diamond film on the PS surface by microwave plasma assisted chemical vapor deposition (MPCVD) method, was developed. The morphologies, structure and photoluminescence (PL) of porous silicon and diamond film were characterized using atomic force microscopy, scanning electron microscopy, X-ray diffraction, Raman spectrometer and PL spectrometer. The results indicated that the homogeneous and dense diamond film could be obtained by MPCVD method on PS, which stabilized greatly the luminescent wavelength and intensity, and moreover enhanced the mechanical strength of PS..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 753 (2001)
Spectroscopic Properties of Er3+ and Yb3+/Er3+-Doped LaLiP4O12 Glasses
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The tetraphosphate glasses with Er 3+ and Yb 3+ /Er 3+ dopant were prepared. The absorption and fluorescence emission spectra were measured, and the emission cross-section for 4I 13/2 → 4I 15/2 transition of Er 3+ was calculated by using McCumber theory. Spectroscopic properties, concentration quenching, and the effectThe tetraphosphate glasses with Er 3+ and Yb 3+ /Er 3+ dopant were prepared. The absorption and fluorescence emission spectra were measured, and the emission cross-section for 4I 13/2 → 4I 15/2 transition of Er 3+ was calculated by using McCumber theory. Spectroscopic properties, concentration quenching, and the effect of -OH groups on the emission at 1.54 μm in these glasses were investigated with diode laser at 970 nm. The optimization of Yb 3+ and Er 3+ ion concentrations are 1.82×10 21 ions/cm 3 and 0.96×10 20 ions/cm 3 respectively in the glasses..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 757 (2001)
Nonlinear Optics
Photo-Induced Birefringence and Bicolor Image Storage in Azo-Doped Polymer Film
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new type molecule [3-azo-(4′-nitro)]-(9-ethyl)-carbazole (ANECz) doped in poly (methyl methacrylate) (PMMA) was synthesized and studied. The polymer film possesses large magnitude of photo-induced birefringence (δn=1.8×10 -2 ). Bicolor image storage has been performed by degenerate four-wave mixing (DFWM) techniA new type molecule [3-azo-(4′-nitro)]-(9-ethyl)-carbazole (ANECz) doped in poly (methyl methacrylate) (PMMA) was synthesized and studied. The polymer film possesses large magnitude of photo-induced birefringence (δn=1.8×10 -2 ). Bicolor image storage has been performed by degenerate four-wave mixing (DFWM) technique. The competition mechanism of bicolor storage was analyzed. Both photoelectric and image storage records were presented..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 679 (2001)
Second Order Nonlinear Optical Effect in Ge-As-S System under the Electron-Beam
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The method of Maker fringes was used and the second order nonlinear optical effect was observed in the electron-beam irradiated Ge-As-S glasses. The mechanism of this effect was discussed. It′s shown from the Maker fringes that the second harmonic intensity is strongly related to accelerating voltage, which gets a peakThe method of Maker fringes was used and the second order nonlinear optical effect was observed in the electron-beam irradiated Ge-As-S glasses. The mechanism of this effect was discussed. It′s shown from the Maker fringes that the second harmonic intensity is strongly related to accelerating voltage, which gets a peak when the incidence of angle is ±(50°～60°)..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 683 (2001)
Optical Devices
Manufacture of a Double Polarization Structure of Polarization Maintaining Fiber Polarizer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A double polarization structure and the result used in manufacturing polarization maintaining fiber polarizer are reported. By comparing the test results of single and double polarization structure fiber polarizers, the conclusion can be drawn that the double one is a useful structure to improve the extinction ratio anA double polarization structure and the result used in manufacturing polarization maintaining fiber polarizer are reported. By comparing the test results of single and double polarization structure fiber polarizers, the conclusion can be drawn that the double one is a useful structure to improve the extinction ratio and temperature characteristics..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 741 (2001)
Model and Optimization of a Novel Detector for Light Radiation
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The theoretical model of the microcantilever used in the light radiation is given based on the theoretical analysis. A novel detector is designed after the optimization about the material of the microcantilever, the coating and the radiation absorbing layer. Compared with the traditional ones, the sensitivity of this nThe theoretical model of the microcantilever used in the light radiation is given based on the theoretical analysis. A novel detector is designed after the optimization about the material of the microcantilever, the coating and the radiation absorbing layer. Compared with the traditional ones, the sensitivity of this new model is made more than twenty times improvement and the noise-equivalent power is decreased 85%～70%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 744 (2001)
Absolute Spectral Responsivity Standard Detectors with Uncertainty Less than 0.035%
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The design and principle of reflective trap detectors are discussed which consist of three windowless Hamamatsu S1337-11 silicon photodiodes. Linearity, spatial uniformity, polarization sensitivity and stability of the trap detectors were measured. By calibration against a CryoRad-Ⅱ cryogenic radiometer, absolute spectThe design and principle of reflective trap detectors are discussed which consist of three windowless Hamamatsu S1337-11 silicon photodiodes. Linearity, spatial uniformity, polarization sensitivity and stability of the trap detectors were measured. By calibration against a CryoRad-Ⅱ cryogenic radiometer, absolute spectral responsivity of the trap detectors was obtained between 488 nm～786 nm with uncertainty less than 0.035%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 749 (2001)
Physical Optics
Ultra-Short Intense Laser Pulse Propagating in Atmosphere: Behavior of Self-Focusing
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The behavior of self focusing of the ultra short intense laser pulse during propagating in atmosphere was studied, particularly, using the numeric solution of a time dependent Schdinger equation on account of Kerr effect and multi photon ionization (MPI) effect. The result implies the intermittence, rather than the stThe behavior of self focusing of the ultra short intense laser pulse during propagating in atmosphere was studied, particularly, using the numeric solution of a time dependent Schdinger equation on account of Kerr effect and multi photon ionization (MPI) effect. The result implies the intermittence, rather than the stable structure, of the filamentation caused by self focusing. Each on axis filamentation will decay due to the ionization while the off axis energy will replenish to the on axis region intermittently due to Kerr effect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 641 (2001)
Solitary Evolution of Gauss Beam in Photovoltaic-Photorefractive Crystal
[in Chinese], [in Chinese], and [in Chinese]
The impact of an applied field on the propagation of a Gauss beam in the photovotaic-photorefractive crystal is investigated. It indicates that, in a photovotaic-photorefractive crystal with a proper applied field, a Gauss beam can evolve into steady-state bright screening-photovoltaic optical soliton. If the applied fThe impact of an applied field on the propagation of a Gauss beam in the photovotaic-photorefractive crystal is investigated. It indicates that, in a photovotaic-photorefractive crystal with a proper applied field, a Gauss beam can evolve into steady-state bright screening-photovoltaic optical soliton. If the applied field is not proper, the Gauss beam will experience cycles of compression and expansion. The intensity and polarity of the applied field have a remarkable influence on the wave shape of steady state bright screening-photovoltaic optical soliton. However, the polarity has a larger influence on it as compared with the intensity of the applied field..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 647 (2001)
Rapid Communications
A Study on Borate-Lead Glasses with Eu3+ Ion as Probe
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The Eu 3+ probe technique is used to the analysis of borate-lead glasses system of (79 5-x)BO 3/2 -(20+x)PbF 2-0 5Eu 2O 3(x=0,10,20,30,40). The excitation spectra for several glasses are measured, the phonon side-band spectra and electron-phonon coupling constant are obtained. The multi-phonon non-radioactive transitioThe Eu 3+ probe technique is used to the analysis of borate-lead glasses system of (79 5-x)BO 3/2 -(20+x)PbF 2-0 5Eu 2O 3(x=0,10,20,30,40). The excitation spectra for several glasses are measured, the phonon side-band spectra and electron-phonon coupling constant are obtained. The multi-phonon non-radioactive transition probabilities are discussed. The emission spectra of Eu 3+ originated from 5D 0→ 7F 0, 7F 1, 7F 2 transitions under 362 nm excitation in this glass system and the optical transitions J-O parameter Ω 2 are obtained, the structure properties of borate-lead glasses are analysed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 762 (2001)
Study of 1410 nm Wavelength Region Distributed Fiber Raman Gain Amplifier
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The operation principle of distributed fiber Raman gain amplifier is discussed. The light amplification was obtained at 1410 nm wavelength region by using a 1320 nm solid laser as pumping source and a 23 km single mode GI optical fiber. The relation between the gain of fiber Raman amplifier and the effective interactioThe operation principle of distributed fiber Raman gain amplifier is discussed. The light amplification was obtained at 1410 nm wavelength region by using a 1320 nm solid laser as pumping source and a 23 km single mode GI optical fiber. The relation between the gain of fiber Raman amplifier and the effective interaction length of optical fiber is studied. When the pump peak power is 50 W and 30 W, the effective interaction length is 15.5 km and 10.5 km. The relation between the gain of Raman amplifier and pump power at different effective interaction length of optical fiber is anlyzed. The spectrum width of Raman fiber amplifier is estimated to be 50 nm or 250 cm from the Raman backscattering spectrum of optical fiber..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 766 (2001)
Thin Films
Strong UV Reflecting Characteristics of Cu/Ti Superlattic Films
[in Chinese], [in Chinese], and [in Chinese]
One-dimensional and two-component Cu/Ti superlattice films have been deposited by DC magnetron sputtering. The influences of substrate temperature, periodic number and substrate structure on UV-reflectivity of Cu/Ti superlattic films are studied. The films fabricated at 470 ℃ substrate temperature, on Si(100) substrateOne-dimensional and two-component Cu/Ti superlattice films have been deposited by DC magnetron sputtering. The influences of substrate temperature, periodic number and substrate structure on UV-reflectivity of Cu/Ti superlattic films are studied. The films fabricated at 470 ℃ substrate temperature, on Si(100) substrate and with 30 pair layers have a high UV-reflectivity of about 90% at 200 nm and 5° from normal incidence..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 673 (2001)
Blue Luminescence from α-Si∶H Thin Film Oxidized by Low-Temperature Plasma
[in Chinese], [in Chinese], and [in Chinese]
Luminescence characteristies of α-Si∶H thin film oxidized by low-temperature plasma was investigated. Strong blue photoluminescence peaks centered at 460 nm,465 nm,472 nm,478 nm,485 nm,490 nm and 496 nm ranging from 450 nm～500 nm were observed at room temperature. The result shows that strength of the photoluminescenceLuminescence characteristies of α-Si∶H thin film oxidized by low-temperature plasma was investigated. Strong blue photoluminescence peaks centered at 460 nm,465 nm,472 nm,478 nm,485 nm,490 nm and 496 nm ranging from 450 nm～500 nm were observed at room temperature. The result shows that strength of the photoluminescence peak increases with the cycle number of deposition-oxidation during preparation. Blue luminescence peaks originate luminescence centers related to O-Si defect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 21, Issue 6, 676 (2001)
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